Page:Tree Crops; A Permanent Agriculture (1929).pdf/37

 that man domesticated and to the first wild grass whose seed was planted. What might not happen if every wild crop-bearing tree was improved to its maximum efficiency? Burbank and others have given us an inkling of what may result from well-planned selection, crossing, or hybridizing.

The possibilities, at present quite incalculable, that lie in such work are hinted in one almost unbelievable statement of the great authority. Sargent, who says of the English walnut, which we all know is so good and meaty:

"The nut of the wild tree is small, with a thick hard shell and small kernel, and is scarcely edible; but centuries of cul-